Re: [QE-users] Advices on ralaxing perovskite supercells
Hello, Laura, I've got the calculation to converge by reducing mixing_beta to 0.3 and increasing conv_thr to 1E-4 for the first calculation and then decreasing it in subsequent calculations using the previously converged ionic positions. Now I'm having troubles trying to do the relaxation with conv_thr = 1E-6, etot_conv_thr = 1E-5 and forc_conv_thr = 1E-4, total force is raising with each bfgs step. Maybe I will have to keep the default values for etot_conv_thr and forc_conv_thr. Also a good starting point is important. Try your best to include from the start the correct octahedral rotations and any other ionic displacement your material may present. Best regards, Luiz Em Seg, Março 16, 2020 11:00 am, Weißhoff, Laura escreveu: > Dear QE Users, > > > > I have a question regarding the Topic "Advices on ralaxing perovskite > supercells" from Luiz G. D. Silveira. > > > Since I am trying to relax a perovskite as well and it neither works for > me, I was wondering if there was a solution for the Problem and if you > can help me as well. > > > Thanks in advance and best regards, > > > Laura > > ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] Advices on ralaxing perovskite supercells
total force is raising with each bfgs step. Maybe I will have to keep the default values for etot_conv_thr and forc_conv_thr. That is normal if you start from a saddle point, although it should decrease eventually cheers -- Lorenzo Paulatto - Paris ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] Advices on ralaxing perovskite supercells
If you haven't already done it, add a small smearing, as for a metal, even if the system is an insulator. Paolo On Mon, Mar 16, 2020 at 3:00 PM Weißhoff, Laura < lweis...@students.uni-mainz.de> wrote: > Dear QE Users, > > > I have a question regarding the Topic "Advices on ralaxing perovskite > supercells" from Luiz G. D. Silveira. > > > Since I am trying to relax a perovskite as well and it neither works for > me, I was wondering if there was a solution for the Problem and if you can > help me as well. > > > Thanks in advance and best regards, > > Laura > ___ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
Re: [QE-users] Advices on ralaxing perovskite supercells
Dear QE Users, I have a question regarding the Topic "Advices on ralaxing perovskite supercells" from Luiz G. D. Silveira. Since I am trying to relax a perovskite as well and it neither works for me, I was wondering if there was a solution for the Problem and if you can help me as well. Thanks in advance and best regards, Laura ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
[QE-users] Advices on ralaxing perovskite supercells
Greetings, I am using QE 6.4.1 to relax the atomic positions of a BiFeO3 40 atom supercell, but the calculation didn't converge after 100 scf steps (the final scf accuracy was about 5E-4). I am a new QE user and I really don't know what to change in order to the calculation successfully run. Any advice is very much appreciated. My input follows bellow: calculation = 'relax' prefix = 'bfo' pseudo_dir = './sssp' outdir = './outdir' etot_conv_thr = 1.0e-5 forc_conv_thr = 1.0e-4 / ibrav = 0 nat = 40, ntyp = 3, ecutwfc = 120, ecutrho = 960 lda_plus_u = .TRUE., Hubbard_U(2) = 4 / conv_thr = 1e-6 / ion_dynamics = 'bfgs' / ATOMIC_SPECIES Bi 208.98 Bi_pbe_v1.uspp.F.UPF Fe 55.85 Fe.pbe-spn-kjpaw_psl.0.2.1.UPF O 16 O.pbe-n-kjpaw_psl.0.1.UPF ATOMIC_POSITIONS (crystal) Bi 0.000 0.000 0.000 Bi 0.500 0.000 0.000 Bi 0.000 0.500 0.000 Bi 0.500 0.500 0.000 Bi 0.000 0.000 0.500 Bi 0.500 0.000 0.500 Bi 0.000 0.500 0.500 Bi 0.500 0.500 0.500 Fe 0.250 0.250 0.250 Fe 0.750 0.250 0.250 Fe 0.250 0.750 0.250 Fe 0.750 0.750 0.250 Fe 0.250 0.250 0.750 Fe 0.750 0.250 0.750 Fe 0.250 0.750 0.750 Fe 0.750 0.750 0.750 O 0.187667999289205 0.312332000710795 0.000 O 0.812332000710795 0.187667999289205 0.000 O 0.312332000710795 0.687667999289205 0.000 O 0.687667999289205 0.812332000710795 0.000 O 0.312332000710795 0.187667999289205 0.500 O 0.687667999289205 0.312332000710795 0.500 O 0.187667999289205 0.812332000710795 0.500 O 0.812332000710795 0.687667999289205 0.500 O 0.000 0.187667999289205 0.312332000710795 O 0.500 0.312332000710795 0.187667999289205 O 0.000 0.812332000710795 0.187667999289205 O 0.500 0.687667999289205 0.312332000710795 O 0.000 0.312332000710795 0.687667999289205 O 0.500 0.187667999289205 0.812332000710795 O 0.000 0.687667999289205 0.812332000710795 O 0.500 0.812332000710795 0.687667999289205 O 0.312332000710795 0.000 0.187667999289205 O 0.687667999289205 0.000 0.312332000710795 O 0.187667999289205 0.500 0.312332000710795 O 0.812332000710795 0.500 0.187667999289205 O 0.187667999289205 0.000 0.812332000710795 O 0.812332000710795 0.000 0.687667999289205 O 0.312332000710795 0.500 0.687667999289205 O 0.687667999289205 0.500 0.812332000710795 K_POINTS (automatic) 4 4 4 0 0 0 CELL_PARAMETERS (angstrom) 7.8 0.0 0.0 0.0 7.8 0.0 0.0 0.0 7.8 Best regards, Luiz G. D. Silveira Universidade Federal do Paraná - Brazil ___ Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
